Brothers Ben and Tom Curry have signed five-year contracts with Sale Sharks.
The 18-year-old identical twins have come through the club's academy to impress in nine Premiership appearances between them this season.
Both play in the back row and have also featured for the England Under-20 side.
"They will play key parts in the club's vision of developing players in the academy, and bringing them through to the first team," Sale director of rugby Steve Diamond said.
The pair became only the fourth set of twins to play side-by-side in the Premiership when they appeared in Sale's 34-24 defeat by Wasps on 27 November.
Tom is also the Sharks' youngest Premiership try scorer after crossing on his debut in the 31-13 win over Bristol on 30 October.